ISO 14222:2022

INTERNATIONAL ISO
STANDARD 14222
Second edition
2022-03
Space environment (natural and
artificial) — Earth's atmosphere from
ground level upward
Environnement spatial (naturel et artificiel) — Haute atmosphère
terrestre
Reference number
ISO 14222:2022(E)
© ISO 2022

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ISO 14222:2022(E)
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© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
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ISO 14222:2022(E)
Contents  Page
Foreword .iv
Introduction .v
1 Scope . 1
2  Normative references . 1
3  Terms and definitions . 1
4  Symbols and abbreviated terms.6
5  General concept and assumptions .7
5.1 Earth's atmosphere model use . 7
5.1.1 General . 7
5.1.2 Application guidance . 7
5.2 Earth wind model use . 8
5.3 Robustness of standard . 8
5.4 Long-term changes of the atmosphere . 8
Annex A (informative) Neutral atmospheres .10
Annex B (informative) Natural electromagnetic radiation and indices .32
Bibliography .47
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ISO 14222:2022(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles,
Subcommittee SC 14, Space systems and operations.
This second edition cancels and replaces the first edition (ISO 14222:2013), which has been technically
revised.
The main changes are as follows:
— updated formulae, references to models, indices and links to websites;
— this document now applies to the Earth's atmosphere from ground level upward through the
exosphere.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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ISO 14222:2022(E)
Introduction
This document provides guidance for determining the properties of the Earth’s atmosphere from
ground level upward to the exosphere.
In the atmospheric regions up to approximately 100 km, a detailed knowledge of the average structure
of the atmosphere as a function of geographic location, time in the year and solar activity is critical
for the design of aircraft, balloon payloads, rocket launch activities and many other facets of modern
society. The maximum departures from average conditions also need to be understood in order to
provide a margin of safety in design and in operations. These features are included in this document.
A good knowledge of temperature, total density, concentrations of gas constituents, and pressure in
the region above about 100 km is important for many space missions exploiting the low-earth orbit
(LEO) regime below approximately 2 500 km altitude. In addition to the causes of variation of the
atmosphere up to 100 km, geomagnetic processes may seriously affect the structure and dynamics
of the thermosphere. Aerodynamic forces on the spacecraft, due to the orbital motion of a satellite
through a rarefied gas which itself can have variable high velocity winds, are important for planning
satellite lifetime, maintenance of orbits, collision avoidance manoeuvring and debris monitoring,
sizing the necessary propulsion system, design of attitude control system, and estimating the peak
accelerations and torques imposed on sensitive payloads. Surface corrosion effects due to the impact
of large fluxes of atomic oxygen are assessed to predict the degradation of a wide range of sensitive
coatings of spacecraft and instruments. The reactions of atomic oxygen around a spacecraft can also
lead to intense “vehicle glow”.
The structure of Earth’s atmosphere and internationally accepted empirical models that specify the
details of the atmosphere are included in this document. The annexes and references provide a detailed
description the details of those models. The purpose is to create a standard method for specifying
Earth's atmosphere properties (density, temperature, wind etc.) at all altitudes from ground level
upward, including the low Earth orbit regime now widely-used for space systems and space operations.
The details of those models are included in Annex A.
Annex B provides a detailed description of the electromagnetic radiation and solar and geomagnetic
indices.
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INTERNATIONAL STANDARD ISO 14222:2022(E)
Space environment (natural and artificial) — Earth's
atmosphere from ground level upward
1 Scope
This document specifies the structure and properties of the Earth’s atmosphere from ground
level upward. It provides internationally accepted empirical models that specify the details of the
atmosphere. It also refers to widely-accepted physical models providing insight into the physical and
chemical processes driving the response of the atmosphere.
2  Normative references
There are no normative references in this document.
3  Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
homosphere
region of the atmosphere that is well mixed
Note 1 to entry: The major species proportional concentrations are independent of height and location.
Note 2 to entry: This region extends from 0 km to ~100 km and includes the temperature-defined regions of the
troposphere (3.2) (surface up to ~6 km to 18 km altitude), the stratosphere (3.3) (~6 km to 18 km up to 50 km
altitude), the mesosphere (3.4) (~50 km up to about 90 km altitude), and the lowest part of the thermosphere (3.5)
(~90 km to 125 km).
3.2
troposphere
lowest layer of the Earth’s atmosphere
Note 1 to entry: It is also where nearly all weather conditions occur.
Note 2 to entry: The troposphere contains approximately 75 % of the atmosphere’s mass and 99 % of the total
mass of water vapour and aerosols. The average height of the tropopause is 18 km (11 mi; 59 000 ft) in the tropics,
17 km (11 mi; 56 000 ft) in the middle latitudes, and 6 km (3.7 mi; 20 000 ft) in the polar regions in winter. The
global average height of the tropopause is 13 km.
Note 3 to entry: The lowest part of the troposphere, where friction with the Earth's surface influences air flow,
is called the planetary boundary layer. The boundary layer is typically a few hundred metres to 4 km deep
depending on the landform, latitude, season and time of day. The upper boundary of the troposphere is the
tropopause, which is the border between the troposphere and stratosphere (3.3). The tropopause is an inversion
layer, where the air temperature ceases to decrease with height and remains constant through its thickness.
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ISO 14222:2022(E)
3.3
stratosphere
second major layer of Earth’s atmosphere, immediately above the troposphere (3.2) and below the
mesosphere (3.4)
Note 1 to entry: The stratosphere is stratified (layered) in temperature, with warmer layers higher and cooler
layers closer to the Earth; this increase of temperature with altitude is a result of the absorption of the Sun's
ultraviolet radiation by the ozone layer. This is in contrast to the troposphere (3.2), near the Earth's surface,
where temperature decreases with altitude. The border between the troposphere (3.2) and stratosphere, the
tropopause, marks where this temperature inversion begins. Near the equator, the stratosphere starts at as high
as 18 km, around 17 km at midlatitudes, and at about 6 km at the poles. Temperatures range from an average
of −51 °C near the tropopause to an average of −15 °C near the stratopause [the boundary with the mesosphere
(3.4)]. Stratospheric temperatures also vary within the stratosphere as the seasons change, reaching particularly
low temperatures in the polar night (winter). Winds in the stratosphere can far exceed those in the troposphere
(3.2), reaching near 60 m/s in the Southern polar vortex.
3.4
mesosphere
layer of the Earth’s atmosphere that is directly above the stratosphere (3.3) and directly below the
thermosphere (3.5)
Note 1 to entry: In the mesosphere, temperature decreases as the altitude increases. This characteristic is used
to define its limits: it begins at the top of the stratosphere (3.3) (sometimes called the stratopause), and ends at
the mesopause, which is the coldest part of Earth's atmosphere with temperatures frequently below −143 °C. The
exact upper and lower boundaries of the mesosphere vary with latitude and with season (higher in winter and at
the tropics, lower in summer and at the poles), but the lower boundary is usually located at heights from 50 km to
65 km above the Earth's surface and the upper boundary (mesopause) is usually around 85 km to 100 km.
Note 2 to entry: The stratosphere (3.3) and the mesosphere are collectively referred to as the “middle atmosphere”,
which spans heights from approximately 10 km to 100 km. The mesopause, at an altitude of 80 km to 90 km,
separates the mesosphere from the thermosphere (3.5) – the second-outermost layer of the Earth's atmosphere.
This is also approximately the same altitude as the turbopause. Below the turbopause, different chemical species
are well mixed due to turbulent eddies. Above this level the atmosphere becomes non-uniform; also, above the
turbopause, the scale heights of different chemical species differ by their molecular masses.
3.5
thermosphere
region of the atmosphere between the temperature minimum at the mesopause (~90 km) and the
altitude where the vertical scale height is approximately equal to the mean free path (400 km to 600 km
altitude, depending on solar and geomagnetic activity levels)
Note 1 to entry: At its lower boundary with the mesosphere (3.4), the composition is close to that found at ground
level. In the upper thermosphere, the composition is usually mainly atomic oxygen.
3.6
exosphere
region of the atmosphere that extends from the top of the thermosphere (3.5) outward
3.7
NRLMSIS 2.0
Naval Research Laboratory mass spectrometer, incoherent scatter radar extended model
model that describes the neutral temperature and species densities in Earth's atmosphere from ground
level upward, including the troposphere (3.2), stratosphere (3.3), mesosphere (3.4), thermosphere (3.5)
and exosphere (3.6)
Note 1 to entry: It is based on a very large underlying set of supporting data from satellites, rockets, and radars,
with extensive temporal and spatial distribution. It has been extensively tested against experimental data by the
international scientific community. The model has a flexible mathematical formulation.
Note 2 to entry: It is valid for use from ground level to the exosphere (3.6). Two indices are used in this model:
F (both the daily solar flux value of the previous day and the 81-day average centred on the input day) and A
10,7 p
(geomagnetic daily value)
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ISO 14222:2022(E)
Note 3 to entry: See References [1] and [2].
3.8
Earth GRAM 2016
Earth GLOBAL reference atmosphere models
models which have been produced on behalf of NASA to describe the terrestrial atmosphere from
ground level upward for operational purposes
Note 1 to entry: Earth GRAM 2016 is now available as an open-source C++ computer code that can run on a variety
of platforms including PCs and UNIX stations. The software provides a model that offers values for atmospheric
parameters such as density, temperature, winds, and constituents for any month and at any altitude and location
within the Earth's atmosphere. An earlier version, Earth GRAM 2010 is available in FORTRAN.
Note 2 to entry: Earth GRAM 2016 includes the troposphere (3.2), stratosphere (3.3), mesosphere (3.4),
thermosphere (3.5) and exosphere (3.6).
Note 3 to entry: These models now include options for NRLMSIS 2.0, HWM-14 and JB2008.
Note 4 to entry: See https:// software .nasa .gov/ software/ MFS -32780 -2.
Note 5 to entry: It is based on a very large underlying set of supporting data from satellites, rockets, and radars,
with extensive temporal and spatial distribution. It has been extensively tested against experimental data by the
international scientific community. The model has a flexible mathematical formulation.
Note 6 to entry: It is valid for use from ground level to the exosphere (3.6). Two indices are used in this model:
F (both the daily solar flux value of the previous day and the 81-day average centred on the input day) and A
10,7 p
(geomagnetic daily value)
Note 7 to entry: See References [3] and [4].
3.9
JB2008
Jacchia-Bowman 2008 model
model that describes the neutral temperature and the total density in Earth’s thermosphere (3.5) and
exosphere (3.6)
Note 1 to entry: See https:// spacewx .com/ jb2008/ .
Note 2 to entry: Its new features lead to a better and more accurate model representation of the mean total
density compared with previous models, including the NRLMSISE-00 and NRLMSIS 2.0.
Note 3 to entry: It is valid for use from an altitude of 120 km to 2 500 km in the exosphere (3.6). Four solar indices
and two geomagnetic activity indices are used in this model: F (both tabular value one day earlier and the 81-
10,7
day average centred on the input time); S (both tabular value one day earlier and the 81-day average centred
10,7
on the input time); M (both tabular value five days earlier and the 81-day average centred on the input time);
10,7
Y (both tabular value five days earlier and the 81-day average centred on the input time); a (3 h tabular
10,7 p
value); and D (1 h value) (a and D are both used as inputs to create a dT temperature change tabular value on
st p st c
the input time).
Note 4 to entry: See References [5] and [6].
3.10
HWM14
horizontal wind model
comprehensive empirical global model of horizontal winds in the atmosphere
Note 1 to entry: Reference values for the a index needed as input for the wind model are given in Annex A.
p
Note 2 to entry: HWM14 does not include a dependence on solar EUV irradiance. Solar cycle effects on
thermospheric winds are generally small during the daytime, but can exceed 20 m/s at night.
Note 3 to entry: HWM14 thermospheric winds at high geomagnetic latitudes during geomagnetically quiet
periods should be treated cautiously.
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ISO 14222:2022(E)
Note 4 to entry: See References [7] and [8].
3.11
DTM-2013
drag temperature model 2013
model that describes the neutral temperature and (major and some minor) species densities in the
Earth’s atmosphere between an altitude of 120 km to approximately 1 500 km
Note 1 to entry: DTM-2013 is based on a large database going back to the early ‘70s, but it is mainly constructed
with high-resolution CHAMP and GRACE accelerometer-inferred data and GOCE thruster-inferred densities.
Note 2 to entry: It is valid from an altitude of 120 km to approximately 1 500 km in the exosphere (3.6). Two
indices are used in this model: F solar flux (both daily solar flux of the previous day and the average of the
30
previous 81-days) and K (3 h value delayed by 3 h and the average of the last 24 h).
p
Note 3 to entry: The DTM model codes (DTM-2009 and DTM-2013) are available for download on the SWAMI
project website (swami-h2020.eu/).
Note 4 to entry: See References [9] and [10].
3.12
reanalysis model
model that provides access to corrected data sets for any location and any time around the world
EXAMPLE ERA5 (3.13) and NCEP/NCAR reanalysis (3.14).
Note 1 to entry: Reanalysis models provide specific data for locations and periods of interest (e.g. inter-
comparison and calibration measurements) and can also be used to provide examples of extrema of atmospheric
conditions, contrasting with the long-term averages represented by the empirical models described in 3.7 to 3.11.
3.13
ERA5
latest ECMWF (European Centre for Medium Range Weather Forecasting) meteorological reanalysis
project
[11]
Note 1 to entry: The first ECMWF reanalysis product, ERA-15 , generated reanalyses for approximately 15
years, from December 1978 to February 1994. The second product, ERA-40 (originally intended as a 40-year
reanalysis) begins in 1957 (the International Geophysical Year) and covers 45 years to 2002. As a precursor to a
revised extended reanalysis product to replace ERA-40, ECMWF released ERA-Interim, which covers the period
from 1979 to present.
[11],[12]
Note 2 to entry: ERA5 is a new reanalysis product which has recently been released by ECMWF as part of
Copernicus Climate Change Services.
Note 3 to entry: This product has higher spatial (horizontal) resolution (31 km) and covers the period from 1979
to present. Extension back to 1950 is now available.
Note 4 to entry: In addition to reanalysing all the old data, now using a consistent system, the reanalyses also
make use of much archived data that was not available to the original analyses. This allows for the correction of
many historical hand-drawn maps, where the estimation of features was common in areas of data sparsity. ERA5
also has the ability to create new maps of parameters at specific atmosphere levels that were not commonly used
until more recent times.
Note 5 to entry: Accessing the data: The ERA5 data can be downloaded for research use from ECMWF's homepage
(see https:// apps .ecmwf .int/ data -catalogues/ era5/ ?class = ea) and the National Center for Atmospheric Research
data archives. Both require registration.
Note 6 to entry: A Python web API can be used to download a subset of parameters for a selected region and time
period.
Note 7 to entry: ERA5 is a reanalysis model (3.12).
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ISO 14222:2022(E)
3.14
NCEP/NCAR reanalysis
continually updated globally gridded data set that represents the state of the Earth's atmosphere,
incorporating observations and numerical weather prediction (NWP) model output from 1948 to
present
Note 1 to entry: It is a joint product from the National Center for Environmental Prediction (NCEP) and the
National Center for Atmospheric Research (NCAR).
Note 2 to entry: Accessing the data: The data is available for free download from the NOAA Earth System
[13] [14]-[18]
Research Laboratory and NCEP. It is distributed in Netcdf and GRIB files, for which a number of tools
and libraries exist.
Note 3 to entry: It is available for download through the NCAR CISL Research Data Archive on the NCEP/NCAR
[16]
Reanalysis main data page .
[17] [18]
Note 4 to entry: Since then, NCEP-DOE reanalysis 2 and the NCEP CFS reanalysis have been released.
Note 5 to entry: The former focuses in fixing existing bugs with the NCEP/NCAR reanalysis system – most notably
surface energy and usage of observed precipitation forcing to the land surface, but otherwise uses a similar
[18]
numerical model and data assimilation system. The latter is based on the NCEP Climate Forecast System .
Note 6 to entry: See https:// psl .noaa .gov/ data/ gridded/ data .ncep .reanalysis .html.
Note 7 to entry: NCEP/NCAR reanalysis is a reanalysis model (3.12).
3.15
SET HASDM density database
database which is used for scientific studies through a SQL database with open community access
Note 1 to entry: The information content of the database originated from the highly accurate densities used to
create the NORAD satellite catalogue and produced by the US Air Force through its High Accuracy Satellite Drag
Model (HASDM) system.
Note 2 to entry: The historical database covers the period from January 1, 2000 through December 31, 2019. Data
records exist every 3 h during solar cycles 23 and 24.
Note 3 to entry: The database has a grid size of 10° × 15° (latitude, longitude) with 25 km altitude steps between
175 km to 825 km.
Note 4 to entry: A description of the source of the database, its validation, its information content and its
accessibility are provided by Reference [19].
Note 5 to entry: See https:// spacewx .com/ hasdm/ .
3.16
first principles atmospheric models
models that use the physical inputs in terms of energy and momentum to the formulae describing the
behaviour of the atmosphere and as such describe the self-consistent evolution of the whole atmosphere
responding to external forcing from the Sun, the oceans, the magnetosphere and solar wind
Note 1 to entry: They include interactions, calculated self-consistently, with the Earth’s ionosphere at higher
altitudes (upper mesosphere (3.4), thermosphere (3.5)).
Note 2 to entry: See References [20] to [28].
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ISO 14222:2022(E)
3.17
WAM
whole atmosphere model
model developed in collaboration with the NOAA Space Weather Prediction and Environmental
Modeling Centers (SWPC and EMC) by vertical extension of the operational Global Forecast System
(GFS) model over the last decade
Note 1 to entry: The model has demonstrated remarkable performance in simulating climatology and daily
variability of the upper atmosphere and ionosphere driven from below. Coupled to ionosphere-electrodynamics
models, it not only reproduced dramatic variations of ionospheric plasma drifts and density distribution
observed during sudden stratospheric warmings but also demonstrated predictive capability with lead times
up to 2 weeks. WAM has reached a level of maturity to be implemented into operations at the National Weather
Service (NWS).
Note 2 to entry: Within the same timeframe NWS also plans to substantially upgrade GFS to the Next Generation
Global Prediction System (NGGPS). Specific capabilities of NGGPS include in particular a nonhydrostatic
dynamical core and the ability to directly simulate important processes such as tropospheric convection at very
high resolution globally and without the need for parameterization. This opens an opportunity for development
of the Next Generation WAM (NGWAM). Specific requirements for extension of NGGPS into NGWAM will be
discussed and capabilities of the new models in application to the upper atmosphere and ionosphere dynamics,
simulation and prediction presented.
Note 3 to entry: See References [20]to [23].
3.18
CTIPe
coupled thermosphere ionosphere plasmasphere electrodynamics model
model that consists of four distinct components: a global thermosphere (3.5) model; a high-latitude
ionosphere model; a mid and low-latitude ionosphere/plasmasphere model; an electrodynamical
calculation of the global dynamo electric field, with all four components running concurrently and fully
coupled with respect to energy, momentum and continuity
Note 1 to entry: See References [24] to [28].
4  Symbols and abbreviated terms
a the 3 h planetary geomagnetic index given in nT
p
A the daily planetary geomagnetic index given in nT
p
CIRA COSPAR international reference atmosphere
COSPAR Committee on Space Research
D the hourly disturbance storm time ring current index given in nT
st
−22 −2
F the F solar proxy given in units of solar flux, ×10 W m
10 10,7
F the solar energy proxy that is used in the DTM-2013; it corresponds to the solar radio flux
30
emitted by the Sun at 1,000 megaHertz (30 cm wavelength)
−22 −2
M the M solar proxy given in units of solar flux, ×10 W m
10 10,7
−22 −2
S the S solar index given in units of solar flux, ×10 W m
10 10,7
SET Space Environment Technologies
URSI International Union of Radio Science
−22 −2
Y the Y solar index given in units of solar flux, ×10 W m
10 10,7
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ISO 14222:2022(E)
5  General concept and assumptions
5.1  Earth's atmosphere model use
5.1.1 General
NOTE 1 ISO/TR 11225 provides an extensive listing of many empirical and first principles atmospheric models
used since before the beginning of the space age up through the modern era.
[1],[2]
The NRLMSIS 2.0 should be used for calculating both the neutral temperature and the detailed
composition of the atmosphere from ground level upward.
[3],[4]
The Earth GRAM 2016 should be used for calculating the total atmospheric density from ground
level upward.
[5],[6]
The JB2008 model should be used for calculating the total atmospheric density from 120 km to the
exosphere.
[7],[8]
The HWM14 should be used for horizontal winds from ground level upward.
[9],[10]
The DTM-2013 should be used for calculating the total atmospheric density above an a
...